The immunotherapy involves injections of peanut proteins known as peptides.
Researchers may be one step closer to developing a vaccine against peanut allergies after a phase I clinical trial showed promising results.
The immunotherapy treatment, called PVX108, is designed to reset the immune system so those with a peanut allergy can be exposed to peanuts without experiencing an allergic reaction.
The safety of the vaccine was tested over the past 18 months in the initial clinical trial in Australia.
During the research, study participants with peanut allergies were injected with increasing doses of peanut proteins known as peptides. The peptides in the vaccine don’t activate the kinds of cells responsible for extreme reactions to peanuts, reducing the risk for people with the allergy.
The first stage of the trial was designed to test only the safety of the vaccine, with the efficacy of the treatment to be tested in phase II. But researchers say this is a promising step in the right direction.
“Although early stage, these results suggest that a peptide-based approach to peanut allergy immunotherapy could offer significant safety advantages over other approaches in later stages of development,” Dr. Robyn O’Hehir, head of allergy, clinical immunology, and respiratory medicine at Monash University in Melbourne as well as chief medical advisor to Aravax, the company behind the trial, said in a press release.
“This is a significant breakthrough in the search for a safe therapy for peanut allergy, and builds on prior work showing that PVX108 targets the peanut-specific T cells that are believed to be the underlying cause of disease,” she said.
An allergic reaction starts in the immune system, which protects the body from viruses and bacteria.
In people with allergies, the immune system mistakes an otherwise harmless substance, called an allergen, as a threat. When such allergens enter the body of a person with allergies, the immune system reacts by sending antibodies and special white blood cells to attack the invading substance. This causes an allergic reaction.
It’s estimated that 32 million people in the United States have food allergies, with 5.6 million of those being children. That’s around 1 in 13 children with a food allergy, or two for every classroom.
Peanuts are one of the most common allergens. And for people allergic to peanuts, a reaction can be fatal.
“Their immune system has developed IGE antibodies against peanuts so that if the person comes in contact with peanuts, these antibodies can trigger a massive inflammatory cascade within the body, which can cause anywhere from a mild reaction to anaphylactic shock, which is deadly,” Tonya Winders, president and CEO of the Allergy and Asthma Network, told Healthline.
“Currently no treatment exists for food allergy, and it is a great source of anxiety for doctors, patients, and their families, as it can be life-threatening,” she said.
PVX108 is one of many treatments currently being researched for food allergies.
Other therapies include
Oral immunotherapy involves people with allergies consuming a small amount of the allergen in increasing amounts.
This latest vaccine, known as peptide immunotherapy, may provide an alternative that may prove more convenient and with potentially less risk.
“Delivering a treatment that does not have to be taken daily could be a huge advantage and convenience to a patient’s lifestyle. This is more equivalent to the schedule for how maintenance allergen (inhalant or venom) immunotherapy is administered,” Dr. Matthew Greenhawt, director of the Food Challenge and Research Unit at the Children’s Hospital Colorado, told Healthline.
“Peptide immunotherapy may be a more specifically targeted form of therapy that moves beyond desensitization, where the current generation 1 therapies are targeted… In the generation 1 therapies, these require active, daily exposure to the allergen to achieve desensitization, so that has to balance some risk of exposure to the allergen,” he said.
PVX108, if proved successful, could provide more options for those who may not be able to tolerate epicutaneous or oral immunotherapy.
Dr. Maria Garcia-Lloret, a pediatric allergist at the University of California, Los Angeles, says there have been significant advances in food allergy research in recent years.
“For people with peanut allergy, I say you’re in luck, because I think between the two or three approaches… there are options now that weren’t there five years ago. The oral immunotherapy works, but people do have reactions here and there, and it’s not ideal. The vaccine is what everyone wants,” she told Healthline.
Unlike other immunotherapies, PVX108 doesn’t require daily exposure to allergens.
Researchers plan to test the efficacy of the vaccine against peanut allergy in the phase II trial.
“The results of this phase one clinical trial demonstrate that our peptide-based immunotherapy approach has a very favorable safety profile, even in patients with severe peanut allergies. As a result, we are working with the clinical community to design a phase two clinical study of PVX108. We believe that this novel peptide-based immunotherapy has important potential to improve the lives of millions of people with peanut allergies,” Pascal Hickey, CEO of Aravax, said in the press release.
It may be several years before a vaccine for peanut allergy is available, but experts are optimistic.
“This is extremely preliminary. If this happens, it will be fantastic. This is the holy grail for food allergy,” Garcia-Lloret said.
Greenhawt says people should be hopeful but realistic about potential treatment options for their food allergies.
“The first-generation treatment options may not be right for all patients, but more products are being developed and something else may be on the market in the near future,” he said.
“We are better today than we were yesterday, figuratively, and the way the field is evolving, we will be better tomorrow than we were today. This is a time of exceptional hope for the field.”
